Bag placer

ABSTRACT

A BAG PLACER FOR AUTOMATICALLY PICKING UP A BAG FROM A STACK IN A MAGAZINE, OPENING IT AND PLACING IT ON A BAG HOLDER OR THE SPOUT OF A SUPPLY HOPPER RECEIVING MATERIAL TO BE DELIVERED TO THE BAG. THE APPARATUS FOR EFFECTING THE MAGAZINE-TO BAG HOLDER TRANSFER AND FOR OPENING THE BAG COMPRISES A SUCTION CUP ASSEMBLY WHICH IS DISPLACED BACK AND FORTH BETWEEN THE MAGAZINE AND THE BAG HOLDER BY A MOTOR DRIVEN MOTION TRANSMITTING LINKAGE MECHANISM. THIS LINKAGE MECHANSISM IS CONSTRUCTED TO DISPLACE THE SUCTION CUP ASSEMBLY ALONG A MOTION PATH APROACHING THE CONFIGURATION OF AND IS DEFINED BY TWO OPPOSITELY CURVED PORTIONS WHICH ARE SMOOTHLY JOINED TOGETHER BY A SINGLE POINT OR REGION OF INFLEXION. THE LINKAGE MECHANISM FURTHER TRANSLATE UNIFORM ROTARY MOTION OF A POWER OUTPUT MEMBER TO ACCELERATE THE BAG AS IT IS TRANSFERRED FROM THE MAGAZINES TO THE BAG HOLDER ALONG THE S-SHAPED MOTION PATH.

Nov. 16, 1971 Filed Dec. 16, 1968 18 Shoots-Shoot 1 42 9o 1, l/l 48 I34 IN V EN TOR.

ARTHUR J- BURKE BY ATTORNEYS Nov; 16,1971 A. J. BURKE ETAL 3,619,981

BAG PLACER Filed Dec. 16, 1968 18 Sheets-Shoot 2 INVENTOR. ARTHUR J BURKE M +6AW1/ ATTORNEYS NOV. 16, 1971 BURKE EI'AL 3,619,981

BAG PLACER Filed Dec. l6, 1968 1a Shc0ts-Sh0ot 5 INVENTOR ARTHUR J- BURKE ATTOR NEYS Nov. 16, 1971 A. J. BURKE EIAL v 3,619,981

7 BAG PLACER Filed Dec. 16, 1968 18 Sheets-Sheet 4 260 350 '2 H8 348 K 10 H80 5 20 r '08 3|O llillll- "j '06 2.2) /|O4 v H40 INVENTOR ARTHUR J- BURKE ATTORNEYS Nov. 16, 1971 A. J. BURKE ETAL 3,619,981

BAG PLACER I Filed Dec. 16, 1968 18 Sheets-Sheet 5 INVENTOR ARTHUR J- BURKE firm 141v +8alvrna/n/ ATTORNEYS Nov. 16, 1971 J, BURKE E'IAL 3,619,981

' BAG PLACER Filed Dec. 16, 1968 18 Sheets-Sheet G ARTHUR J- BURKE Mai/841mm ATTORNEYS Nov. 16, 1971 J. BURKE ETAL BAG PLACER Filed Dec. 16, 1968 18 Shoots-Sheet |34 mvam-on 2| I400 V2 ARTHUR J. BURKE ATTORNEYJ Nov. 16,197] J, BURKE ETAL 3,619,981

BAG PLACER I Filed Dec. 16, 1968 18 Shoots-Shoat 290 I we 2 I u mvmoa ARTHUR J- BURKE 77W Mid/MM ATTORNEYS Nov. 16, 1971 A. J. BURKE ETAL 3,619,981

BAG PLACER Filed Dec. 16, 1968 18 Shoots-Shoot 1O MAGAZINE ENTRY POSITION ADVANCEMENT OF SUCTION CUPS I40 & I400 RETURN OF SUCTION CUPS f I40 8 I400 DEGREES 0F SUCTION CUP ARM ROTATION I I L BAG TRAVEL sPouT- MAGAZINE BAG I OPENING BAG PICK-UP POSITION INVENTOR ARTHUR J- BURKE ATTORNEYS Nov. 16, 1971 B RKE Em 3,619,981

BAG PLACER Filed Dem 16, 1968 18 SheetsSheet 15 DISCONNECT DEVICE POWER RELAY W PowER ON 131 1- A OUTER cups &

CLOSED wl TH CRANKOARM vcc EXTEND SOLENO'D 460 RAISED 45 .THRU no j M C N 0L M A v uu 0 TR CLOSED WITH CRAONK ARM RC4 I RELAY 462 RAISED ABOVE 50 H/ 0K0 l1 TT/ BV ARMS LowER AuTo CYCLE ICC soLENow 420 cLosE WITH ARMS D 5 I FULL UPGONLY 1; IMPROPER CYCLE OUT IN W RELAY Q I G REsET RELAY BFT-l vcc-z ACY f II/ Q SYSTEM CYCLING m I I RELAY H 426 H EMS ICC-I OPENS WHEN BAGS ,8 RAISED TO PROPER LEvEL MAGAZINE f BlP-l ADC I ELEvAToR 2 D I u k MOTOR STARTER 422 1 432 IIL 11/ INVENIOR AUTO CYCLE VMS-4 ARTHUR J. BURKE :j r440 R ASE Q A MS R HOLD RUN 1 1r SOLENOD 441 BY 1 V M flea/$14M ATTORNEYS Nov. 16', 1971 A. J. BURKE ETAL 3,619,981

BAG PLACER Filed Dec. 16, 1968 18 Sheets-Sheet 14 s% M o A R 434 ADC, I J '2' A ARMgEDOAWN Y 466 oxo-z vac-[ A L A L VACUUM BREAK RELAY A I VACUUM BREAK VALVE 5 & OUTER CUPS 47 474K II I A! VACUUM ON SOL.

v OKD 3 OPEN W/INSUFFICENT VACUUM filly] OK To D'SCHARGE 1 R 1' 2 SCALE RELAY 478 I ran /Cw BAG CLAMP SOL AuTo CYC RC-2 IN ou S ,czv

FOOTSWITCH 552 [I r 544 {IL BIP 1 |a2 I82 RC3 i] BAG IN PLACE RELAY W vi soc CLOSEDWITH BAG 50c- M IN PLACE AT SPOUT p fg r BFT a BAG FILLINGTIMER I ON DELAY I SCALE DISCHARGE IMPULSE FROM SCALE INVENTOR ARTHUR J. BURKE BY M+da2mm ATTORNEYS Nov. 16, 1971 A. J. BURKE ETAL BAG PLACER 18 Shoots-Sheet 15 Filed Dec. 16, 1968.

INVENTOR ARTHUR J- BURKE Nov. 16,1971 ,B RKE- EIAL 3,619,981

BAG PLACER Filed Dec. 16, 1968 l8 Shouts-Shoot 1c 47s 4 444- f 45 g CIT Q, o FV 447 M 444 EV 1 1 .155

442 Y P Q INVENTOR ARTHUR J- BURKE ATTORNEYS Nov. 16, 1971 BURKE ETAL 3,619,981

' BAG PLACER Filed Dec. 16, 1968 18 Sheets-Shoot 1v INVENTOR ARTHUR J- BURKE BY M vfialurrmu ATTORNEYS Nov. 16, 1971 J. B R ETAL 3,619,981

. BAG PLACER Filed Dec. 16, 1968 18 Sheets-Sheet 18 INVENTOR ARTHUR J. BURKE 720W 9flabnnanv ATTORNEYS United States Patent Ofice 3,619,981 BAG PLACER Arthur J. Burke, Oakland, N..I., and Rudolf Keller, New

York, N.Y., assignors to Howe Richardson Scale Company, Clifton, NJ.

Filed Dec. 16, 1968, Ser. No. 783,786 Int. Cl. B65b 43/30 U.S. Cl. 53-190 16 Claims ABSTRACT OF THE DISCLOSURE A bag placer for automatically picking up a bag from a stack in a magazine, opening it and placing it on a bag holder or the spout of a supply hopper receiving material to be delivered to the bag. The apparatus for effecting the magazine-to-bag holder transfer and for opening the bag comprises a suction cup assembly which is dispalced back and forth between the magazine and the bag holder by a motor driven motion transmitting linkage mechanism. This linkage mechanism is constructed to displace the suction cup assembly along a motion path aproaching the configuration of an S and is defined by two oppositely curved portions which are smoothly joined together by a single point or region of inflexion. The linkage mechanism further translates uniform rotary motion of a power output member to accelerate the bag as it is transferred from the magazine to the bag holder along the S-shaped motion path.

FIELD OF INVENTION This invention relates to apparatus for picking up a bag from a stack in a magazine, for opening the bag and for placing it on or presenting it to a spout or the bag holder of a hopper or other receptacle containing ma terial to be delivered to the bag. 'Such machines are commonly referred to as bag placers, bag hangers or bag feeders. The term spout is used herein to designate the lower end of the supply hopper. In some cases the bag is placed directly on the spout and held in place theeron by a suitable bag holder or clamping device. In other cases the bag holder is at the lower end of the spout so that the bag will, in effect, be suspended from the bottom of the spout. The phrase suspending the bag from the spout is used herein to designate either of the cases mentioned above.

BACKGROUND OF THE INVENTION In automatic bag placing and filling machines of the type with which this invention is concerned, a magazine for storing a stack of empty bags is spaced from the spout of a supply hopper containing material for filling the bags. Usually the magazine is horizontally spaced from the general region of the hopper and below the level of the spout which is vertically located at the bottom of the hopper to provide the necessary space for transferring the bag from the magazine to the spout.

Probably the most common form of bag transferring mechanism in use in industry today is the type which swings the bag about a fixed center and, consequently, along an arcuate path of uniform radius. With such transfer mechanisms the level at which the bag is disposed in the magazine is determined by the horizontal spacing between the magazine and the vertical axis of the spout. For relatively long bags, on the order of 20 inches and more, the horizontal distance between a horizontal stack of bags in the magazine and the spout is required to be relatively large to enable the bag to be clear of the magazine when it is placed on the spout. As a result, the vertical spacing between the bag in the magazine and the bottom of the spout will be equally as great. The head room occupied 3,619,981 Patented Nov. 16, 1971 by the bag placing and filling equipment will therefore be considerable.

SUMMARY AND OBJECTS OF INVENTION This invention differs over the foregoing type of bag transfer mechanism and other forms of previously proposed bag placers by providing a bag transfer linkage mechanisms which picks up a bag from a generally horizontal stack in the magazine and which transfers it to the spout along a path having a smoothly curved configuration approaching the shape of an S which is turned generally 60 degrees from its normal, upstanding orientation depending upon the inclination of the bags stacked in the magazine. More specifically, the path along which the bag is advanced from the magazine to the spout is defined by two continuously and oppositely curved sections which are smoothly joined together by a single inflexion.

The first curved section extending from the magazine has in effect a progressively increasing radius such that the bag will initially be lifted from the stack generally upwardly and then advanced more horizontally. The second curved section has a progressively decreasing radius extending from the first curved section to the spout. From the point of infiexion, therefore, the motion of the bag will first be along the straighter portion of the second curved section and then will swing upwardly to the spout where the radius diminishes so that the motion of the bag at the end of the second curved section will be essentially vertical. Thus the value of the second derivative of the bag motion curve, which is described by the gripped bag portions as they move from the magazine to the spout, continuously decreases to zero at the point of infiexion and then continuously increases from the point of inflexion to the end of the curve at the spout.

The foregoing S-shaped motion path allows the spout to be spaced from the magazine at a considerably horizontal distance while at the same time enabling the vertical distance between the spout and magazine levels to be minimized. As a result, the head room occupied by the equipment is correspondingly reduced as compared with the previously described prior art mechanisms.

The foregoing S-shaped motion path is achieved essentially by three parts of a linkage mechanism which drive connects a motor or other prime mover to the apparatus (such as suction cups) for gripping or holding the bag. Two parts are each pivoted about fixed, spaced apart centers or axes, and their opposite ends are pivotally connected to the third part which carries the bag holding or gripping means. The arrangement of pivot points and the ratio of lengths of the three parts provides the S-shaped, bag-transfer motion path described above.

The linkage mechanism of this invention was found to be additionally advantageous in that it starts the bag motion at a relatively slow speed and then rapidly accelerates the bag as it is displaced toward the spout. As a result, there is less likelihood that the bag will be jarred loose from the gripping apparatus by sudden acceleration as it is picked up from the stack in the magazine. Rapid acceleration of the bag after it is picked up reduces the time required for transferring the bag.

The foregoing S-shaped, bag transfer motion path also is effective in improving the reliability of suction cups which are used in this invention for picking up the bag from the magazine, for opening it, and for presenting it to the spout.

According to a further feature of this invention two sets of suction cups are provided for gripping and opening the bag. In its bag pick-up position a first of the two sets is displaced to engage the upwardly facing side of the topmost bag in the generally horizontal stack stored in the magazine. The cups in the second set are initially swung outwardly to extended positions on opposite sides of the stack in the magazine, and as the bag is picked up by the first set, the cups in the second set, upon clearing the stack of bags in the magazine, are swung inwardly to engage the downwardly facing side of the lifted bag. The bag now pinched or gripped between the two suction cup sets continues its advancement toward the spout, and as it approaches the spout, the cups in the two sets are swung outwardly to open the mouth of the bag and to present the opened bag to the bag holder at the spout. The cups in the second set, after they release from the bag, are swung outwardly to their initial extended positions where they will clear the spout mounted bag on their return and where they will clear the stack as they enter the magazine in preparation for transferring the next bag to the spout.

The initial lift applied to the bag in its advancement along the previously described S-shaped motion path is advantageous in that it minimizes the forces tending to separate the bag from the first set of suction cups. As a result, more reliable operation of the bag placer is achieved.

As will become more apparent from the detailed description, the assembly of the two suction cup sets mentioned above is the only means utilized for picking up and transferring the bag from the magazine to the spout. This arrangement provides a simplified construction as compared with prior types of bag placers in which two separate mechanisms are employed, one of which picks the bag up and delivers or presents it to the other mechanism for transfer to the spout.

In the arrangement provided by this invention, the suction cups engage the bag sides at the forward corners thereof adjacent to the open end of the bag. As the bag is initially lifted it is also advanced forwardly, with the horizontal component of travel being iniitially less than the vertical travel component. To keep the bag mouth from opening widely before the cups in the second set are swung inwardly to pinch the bag, one or more streams or jets of air, which are directed from the forward end of the magazine, impinge against the downwardly facing side of the bag adjacent to its open end. This prevents the bag from opening so widely as to interfere with the proper engagement of the second suction cup set mentioned above.

With the foregoing in mind, it is a primary object of this invention to provide a novel bag placer which is efiicient and reliable in operation and which is capable of feeding bags to a supply hopper or the like at a rapid rate.

Another major object of this invention is to provide a bag transfer mechanism which picks the bag from a stack in the magazine and which delivers it to the hopper along a smoothly curved motion path approaching an S- shaped configuration to thereby provide a relatively low vertical distance between the levels of the spout and the stack of bags in the magazine.

Still another object of this invention is to provide a novel, relatively simplified suction cup arrangement for gripping and opening the bag.

Other important objects of this invention include the provision of a novel, electrical circuit for controlling the automatic operation of the bag placer.

Further novel features, additional important objects, and other significant advantages of this invention will become more fully apparent from the appended claims and as the detailed description proceeds in connection with the drawings described below.

DESCRIPTION OF DRAWINGS FIG. 1 is a partially diagrammatic plane view of a bag placer according to a preferred embodiment of this invention and showing the bag-filling, scale hopper in section;

FIG. 2 is a perspective view of the apparatus shown in FIG. I as seen from the direction of the arrow indicated at A in FIG. I;

FIG. 3 is a rear elevation of the magazine shown in FIG. 1;

FIG. 4 is a section taken substantially along lines 44 of FIG. 3;

FIG. 5 is a front view of the magazine as seen from a plane defined by lines 5-5 of FIG. 4;

FIG. 6 is a plane view of the magazine as seen from a. plane defined by lines 66 of FIG. 4;

FIG. 7 is a fragmentary elevation of the bag-engaging suction cup assembly of this invention at its bag pick-up position in the magazine;

FIGS. 8, 9, and 10 are sections taken respectively along lines 88, 99, and l0-10 of FIG. 7;

FIG. 11, which is a section taken substantially along lines 1111 of FIG. 1, illustrates the linkage mechanism for connecting the drive motor or other prime mover to the bag pick-up and transfer mechanism shown in FIG. 7;

FIGS. 12, 13, 14, 15, and 16 are generally diagrammatic elevations as seen from the right-hand side of FIG. 1 and showing the operation of the linkage mechanism illustrated in FIG. 11 as well as operation of the suction cup assemblies illustrated in FIG. 7;

FIG. 17 is a fragmentary perspective view showing the return movement of the suction cup assemblies after the bag is clamped by the bag holder at the bottom of the scale hopper;

FIG. 18 is a graph diagrammatically illustrating the various positions of the suction cups shown in FIG. 7 for picking up a bag from the magazine, for pinching or gripping the bag for transfer to the supply hopper, and for opening the bag during its movement toward the scale hopper;

FIG. 19 is a diagrammatic view of the pneumatic circuit for operating the bag placer shown in FIG. 1;

FIG. 20 is an enlarged, fragmentary elevation of the suction cup positioning mechanism shown in FIG. 11;

FIGS. 21 and 22 are sections respectively taken along lines 21-21 and 2222 of FIG. 20;

FIG. 23 is a section taken substantially along lines 2323 of FIG. 22;

FIG. 24 is a section taken substantially along lines 2424 of FIG. 22;

FIG. 25 is an enlarged, fragmentary elevation of the motion transmitting mechanism shown in FIG. 11 for operatively connecting the bag-transfer linkage mechanism to the suction cup positioning mechanism illustrated in FIGS. 20-24;

FIG. 26 is a section taken substantially along lines 26-26 of FIG. 11;

FIGS. 27A and 27 B schematically illustrate the electrical control circuit for the bag placer, with FIG. 27B being a continuation of the circuit shown in FIG. 27A;

FIG. 27C is a diagrammatic view of the bag-filling scale together with the control circuit therefor;

FIG. 28 is a schematic of the vacuum circuit for the suction cups shown in FIG. 7;

FIG. 29 is a fragmentary, enlarged, partially sectioned elevation of the bag holder shown in FIG. 2;

FIG. 30 is a view generally in planed of a bag height sensing mechanism in operative position on the magazine shown in FIG. 2;

FIG. 31 is a fragmentary front elevation of the bag height sensing mechanism shown in FIG. 30;

FIG. 32 is a section taken along lines 32-32 of FIG. 30; and

FIG. 33 is a diagrammatic view of the bag height sensing mechanism shown in FIG. 30.

DETAILED DESCRIPTION Referring now to the drawings and more particularly to FIGS. 1 and 2, the bag placer, according to the preferred embodiment of this invention, comprises a magazine 20 for storing a stack 21 of collpased, flattened, empty bags and a bag feeding and opening mechanism 22 for automatically picking the top bag in stack 21 and 

